Shoulder firearm



Aug.. l0, 1954 F..P. sLoAN 2,685,814

SHOULDER FIREARM Filed Jan. 27, 1947 3 Sheets-Sheet 2 E 1,06 104 Fay. 8

lll [06 154 109 95 75 3 5a g Sly 5/ l INVENTOR.- me/co P. Slm

Aug- 10, 1954 F. P. sLoAN 2,685,814

SHOULDER FIREARM Filed Jan. 27, 1947 5 Sheets-Sheet 3 iig figa# Egea ngz? B-; so

azi; "Z Je@ "9 INVENTOR: 5L-Fzj30 59 Patented Aug. l0, 1954 UNITED STATES PATENT OFFICE SHOULDER FIREARM Francis I. Sloan, Wilton, Conn.

Application January 27, 19447Seria1 No. 724,562

(Cl,V SS-Z.4)

6 Claims. l

This invention is a novelshoulder firearm, being a gun which is adapted to be manually carried and operated, and which carries both a gun sighting means for use in adjusting gun elevation and a range finding means; these three general elements, the gun, the sights with the setting device for the rear sight, and the settable range nding means being, pursuant to the present invention, combined in mutual interrelation, in a manner to be described, to give advantageous cooperation between said elements in practical use.

The improvement is widely useful, affording an improved construction and operation for rifles and other shoulder firearms of various types such as the U. S. Army Springfield rifle, the Eneld rifle, the Garand rille etc.; a typical instance upon which the invention may be embodied to advantage being the Springfield rifle, bolt-oper ated, semiautomatic in action and handling shot cartridge clips. The invention is particularly useful for war purposes and biggame hunting, with various shooting ranges up to 600 yards more or less.

In the prior art of shoulder firearms, of course,

gunsights have long been standard equipment associate of the gunner, permitting the latter thus to be apprised of the range and appropriately to set his sights accordingly. One important class of range finders is the monocular, which is free of the complications and inconveniences of binocular instruments. No instance is known by applicant of a gun carying in cooperatively combined relation a rear sight setting means and a monocular range finding means.

Brea-diy the present invention presents the association of the three general elements, the gun or shooting firearm, and mounted thereon the sighting means or gunsight for aiming the gun for a given target, and also mounted thereon the means for determining the range of the target to assist the purpose of properly adjusting the rear sight to provide the proper elevation of the gun to cause the trajectory of the fired bullet to meet the distant target; matters of allowance for windage and other factors than elevation being independent factors and unnecessary to elucidate for the purposes of the present invention.

At the outset it may be conceded as having been suggested, before the, present invention, to combine in a broadsense a gunsighting means and some form of rangeA finding means both carried upon a shoulder firearm; but so far as is known these three general elements have not heretofore been operatively combined, at least in monocular form or with a base type of finder, in a manner to afford a cooperative combination of the elements; the gunsight of the most pertinent known prior suggestion serving its function for setting the elevation of the gun, but the range finding means having no more relation to the other elements than its being carried for convenience upon thegun as a handy support, and having no more combination relation or cooperation with the gunsight means than has the rubber eraser at one end of an ordinary pencil with the lead serving the writing function at the other end; on the gun as on the pencil these elements being in aggregation rather than combination, and having distinct disadvantages, such as the non-functional and objectionable adding to the weight ofthe complete gun with gunsight the substantial further weight of a complete rangei-lnding means, which might with greater advantage be operated independently, either by the gunner or an associate, to determine the range of the target in preparation for the corrective sighting and firing of the gun.

It is an object of the present invention to provide en a rearm a novel and useful general combination therewith of gunsight means and range finding means, involving ycoacting features of form, arrangement and structure. A further object is to afford a special and complete rnode of cooperative action of said three elements, by means of novel and specific interrelated features of form, arrangement and structure, including mutual interconnections or a common control serving to provide the aforesaid cooperation in a manner to be hereinafter more specifically described and explained. A particular object is to provide, for a shoulder firearm, and in cooperation with the s ettable shooting sights thereof, a specific type and form of range-finding means, and with such interconnection between the two that when the range-finding operation has been performed and the range thus determined the shooting sights will have become automatically set to produce a gun elevation corresponding to the target range sodetermined.

To the attainment of the recited objects and advantages the present invention consists in the novel shoulder firearm, herein illustratively disclosed and described, and more especially the combination with the firearm or gun itself of its front and rear sights and their setting device and a range-nding means and its setting contrivance, all arranged and operable to afford the actions and results hereinafter more particularly set forth. More particularly the'` invention consists of certain intercombinations of cooperative elements which may be viewed in difierent aspects. In one aspect the irearm hereof has for its front and rear shooting sights a shiftable rear sight setting device to lift or lower` the'- rear sight and so coordinate the elevation of thegun with the range of the target; the gun carrying also mounted thereon al monocular type, as the base type, of range-finder having a shiftable setting member or contrivance operable to determine under visual observation the range of the target; and a common adjuster or controller, as an adjusting cam means, which mechanically interconnects, andis operable under such visual observation to shift and set, in the same action, both said setting device and said setting contrivance in such coordination that when. the adjusting means is operated to setV the rangefinder to the range ofthe target this action automatically setsv the rear sights for a gun elevation corresponding with suchY range.

In another aspect the invention consists of the gun with shooting sights as'before but characterized ink that, cooperative therewith, the gun carries also an optical range finder of the base type wherein plural images of the target are visually observable and may be brought into register or coincidence by the setting of the range finder; the range finder having rear and front optical elements or reflectors spaced apart upon its base line, which base is of substantial xed length and is located adjacently alongside, preferably lengthwise above, the gunV barrel, with its observation point near the rear sight, the

reflector being angularly settable for combining the two' light beams thereby to bring into register the two images of the target; the range nder having a shiftable setting contrivance operable by observation thus to set such rear reflector and thereby bring the plural images inte` mutual register or coincidence, and thus to determine the range ofthe target; sothat the gun may be heldcomfortably by the shooter in its range-observing position transverse to the line of fire or direction of shooting, and with the center of gravity of the gun approximately near the gunners head, providing` an easy balance during the range-finding operation, and so that the gun may thereupon, when the range has been determined, be readily shifted from transverse to longitudinal position for shooting action after the setting of the gun sight to the target range.

In a further and preferred aspect the invention consists. in the complete combination of the elements thus iar recited, with the same gun sights and the setting. device or mechanical connectionsv therefor, also the base-type rangeiinder, mounted with its base line adjacently lengthwise the gun barrel and of substantial length approximately coextensive with that of the barrel, having. also a shiftable setting'contrivance or connections operative to determine under observation the range of the target; combined with the commonA adjusting' means or controller, shown as a c'a'm', which is operably' conlli) nected both to the setting device and to the setting contrivance to shift them simultaneously in such coordination that the elevation of the gun in any and every setting of the sights corresponds automatically with the range determined by the setting of the range finder.

In the accompanying drawings showing an illustrative embodiment of the invention, Fig. 1 is. a range finding diagram in top plan View, with great exaggeration of the angular divergence of the paths of the two light beams received from the target, the firearm being shown as held in iinding position.

Fig. 2, in three parts 2a, 2` and 2C, presents image alignment or registering diagrams, with the gun held horizontal, erect images being .shown in process of alignment upon a given reference line or hair line. Fig. 3 is a similar diagram but with the gun vertical. Fig. 4 is a similar diagram showing alignment when the gun is held in some other or slanted position. Fig. 5 is a diagram showing a different kind of alignment or coincidence, an erect image in register with an inverted one. Fig. 6, in two parts @a and 6b, presents diagrams showing two erect images being. brought into complete coincidence as when a transparent mirror is used to afford simultaneous viewing of superimposed images of an object or target. These various operations are performable upon the gun of the present invention, as will further appear.

Figs. '78L and 7b constitute similar perspective views of the more important rear and front parts of a gun embodying the present invention, with the gun rear. end and much of its middle portion omitted; Fig. '7a showing the breech portion of the gun from the line la of Fig. 1 rearward, while Fig. '7b shows the front portion of the gun from the line 'l'b of Fig. 1 frontward; the base range nder requiring the use of well spaced-apart optical elements or beam-bending reflectors shown as the prisms' A and B near the rear and front ends respectively of the barrel, at the front end there being a beam receiving 0r collecting element and at the rear end a beam combining and viewing unit, at or near the breech.

Fig. 8 is a top plan. View of the breech of the gun together` with the rear sight and the rear or beam-combiningV unit of. the range nder, to'- gether with the various devices, members and mechanisms associated therewith.

Fig. 9 is a righthand elevation of the rear unit mechanism shown in Figs. 7*3B and 8; while Fig. l0 is a front elevation, Fig. 11 a lefthand elevation, and Fig. 12 is a rear elevation of the same.

Fig'. 13 is a front elevation of the muzzle end of the gun showing the front' sight and the beam collecting and transmitting means, all mounted upon the gun barrel. Fig. 14 is a lethand elevation oi the parts` shown in Fig. 13; while Fig. 15 is a righthand elevation, Fig. 16 a rear elevation, and Fig. 17 a top plan view thereof.

Fig. 18 is a top plan view of a certain saddle member or block which'constitutes a base for the rear unit of the invention and which is fitted upon and attached fixed-ly to a cross arch or bridge as conventionally exists at the breech of the firearm. Fig. 19 is a righthand elevation of the right end plate of the saddle of Fig. 18'.

Fig. 20 is a top plan view of a swingable carriage or turret which is supported by the saddle block and which in turn gives support to the beam-combining or rear unit ofthe range finder; and Fig. 21 is a front elevation of said carriage While Fig. 22 a rig-hthand elevation thereof.

Fig. 23 is a perspective view of a frame guide or slideway upon which is slidingly supported a certain rear sight bridge, for rising and lowering adjustment of the latter.

Fig. 24 is a top plan View of the rear sight bridge, while Fig. 25 is a rear elevation thereof; Fig. 25 being a rear elevation of the peep hole plate constituting the rear sight, and Fig. 27 a central vertical section through the same looking from the righthand side; Fig. 28 being a vertical section of the sight bridge of Figs. 24 and 25, taken centrally through the same and looking from the right side; Fig. 29 being a detached top plan view of the sliding plate shown in Fig. 28 which connectsthe sight bridge to the guide or post member shown in Fig. 23, and Fig. 30 a rear elevation of said sliding plate.

Fig. 31 is a top plan View of the housing, shown also in Fig. Ia and Figs. 8 to l2 for the beamcombining rear unit of the range finding means;

. While Fig. 32 is al righthand elevation, Fig. 33 a rear elevation, Fig. 34 a front elevation, and Fig. 35 a left elevation, of the same.

Fig. 36 is a top plan view of the common operating means, controller or adjusting cam preferably employed for eiecting both the sightsetting and the range-iinding adjustments of the invention; while Fig. 37 is a rear elevation of the same; Fig. 38' being a vertical section taken on the line 38-38 of Fig. 37, and Fig. 39 a vertical section taken on the line .3S-39 of Fig. 37.

Fig. 40 is a top plan view showing the beamcomhining unit of the range iinder, and optionally associated therewith a telescope adapted to afford magniiication of observed images during adjusting or range nding operations; Fig. 4l being a front elevation of such telescope, and Fig. 42 a left elevation of the same.

Fig. 43 shows in diagram one form of beam reiiector or prism adapted to receive a normal light beam and reflect it, as internally, for transmission along a light path at substantially right angles to the entering beam.

The drawings show, as one illustration of the invention, a gun 53 of a conventional kind, the term gun being intended to include any shoulder firearm, whether of rifle or other class. Some of the general gun parts are shown and designated by reference number, while other parts are either shown but not so marked or are omitted` as unnecessary for a disclosure of the present invention. The illustrated rearm 53 has the gun barrel El?, of suitable bore, and overlapping therewith the usual gun stock MTX. Associated with these are comprised the conventional cartridge handling and iiring and other operating parts. The firing chamber constitutes a rear enlargement or" the bore, and within it operate the firing bolt and pin, retractible to make way for Athe insertion and extraction of cartridges; there being shown a cartridge-clip slot d4 within the chamber. At the underside of the stock appears the customary trigger 56X, for causing the ring action. Arching across, at the gun breech, below the position of the rear sight t3 to be described is shown the preexisting cross bridge 52, a permanent xed part of the gun, which is utilized as a support for the mounting of the rear sight and its adjusting mechanism, there being shown a saddle block or base member 5i attached ixedly atop the cross bridge 52,

this herein giving mechanical support to the rear sight and to the rear elements of the range-Ender means.

As already indicated, the invention relates bothY to the settable sight means upon a ii-rearm and to the cooperating base-type range iinder thereon. The invention is distinguished from the mere addition of a sighting telescope to a gun, even though the focusing thereof may indicate the range; such a plan adding greatly to the burden of weight and presenting other drawbacks with.- out being of practical value in the setting of the sights to the range. The invention is distinguished also from any plan for the hiere applying upon a gun of a base-type range finder of which the base line is not disposed substantially lengthwise the gun length, or which iinder is operable while the gun is held longitudinal to the line of iire; for in such cases either the range base is too short for accuracy or the structure projects prohibitively crosswise.

The present invention uses the true baseline or triangulation principle (see Fig. 1) and does so in a manner to afford an ample base, namely, by placing it longitudinally to, and thereby using substantially the full length, of the gun barrel, and so giving greatly multiplied accuracy. Two target-viewing optical elements are provided for range iinding, one element or reflector B near the iront sight at the muzzle end, and the other element A adjacent to the rear sight at the breech end of the barrel. These reflectors A and B cooperate to render observable the twice-bent one of the two images required to be set to coincidence in this type of finder. For range-finding, the iirearm hereof is iirst held across the line of nre, with the shooters eye E close to the optical observing element at the breech, as the usual gun sling readily permits. The left hand grips the forestock in the usual manner, the butt rests on the right arm near the elbow and the gun remains steady while the right hand reaches around to the setting thumbscrew or member 53 to be described and thereby adjusts the optical elements until the plural images of the target are brought into register, thus finding the range.

Using the complete invention, with the manual adjusting or. the range--iinding elements under observation, the action simultaneously shifts the setting device of the rear sight t3, and thus sets the sight to deliver the correct gun elevation for the found range. Thereupon the rearm is easily swung 900 into firing position. The left hand continues its grip on the forenstock and the right hand quickly and easily slips down into position for the trigger squeeze. The complete nding and shooting operation are performed naturally and with but little eiort and the eye need not be removed from the target.

The optical elements may be those of any true base type or coincidence range-lnder or telemeter having the two spaced-apart optical elements, namely. the beam-collecting element with reiiector B and the beam-combining element A, thus producing ior the gunners observation the twice-reflected target image and a second or direct image, in one ocular or field of View, the setting means and movements being such that one image may be brought into alignment or coincidence with the other, with a diiierent setting for each range. The beam of one of the images may be twice bent, passing the length of the barrel between reflections, and the second reileotor of this beam, near the rear sight, may be the one by which the setting is eiected, for example by a minute angular swing or rotation upon a pivot or axle, continued manually until therst and second images are seen to be in perfect register.

While a reading of range by scale and index could be made, and then translated manually to sight setting and. elevation; with this invention, as illustrated, the twov operations may be and are coupled, by a duplex common adjusting means, with for example a' single hand piecev as the thumb-nut 83. The rear sight may for this purpose be not only adjustable as to elevation but adapted by its coupling orinterconnection with the moving elements of the range-finder to set ie sight automatically for a gun elevation in accordancewith the range. The iront sight H may be stationary and of any standard type.

As a matter or definitionthe' muzzle end is herein treated as the front end of the gun, and the butt or stock end the' rear; the'l sight nearest the shooter is the rear sight; and when the gun is: in shooting position the view seen from the righthand side of the shooter is considered the right elevation View of the gun, and the same withk the various parts thereof, and vice versa.

The embodiment of the invention which is illustrated in the drawings shows it adapted to the physical structure' and dimensions of the U. S. Army Springiield riile, caliber 30; Model 1903; but the invention is not to be limited/to this firearm or tothe details thereof.

The invention' serves the important purposes, inter alia, of (1) improving the accuracy of rearm aiming by providing a practical finding instrument by which the' gunner can measure reliably the distance over which the bullet is to travel in its curved trajectory; (2) providing for such purpose a portable' coincidence rangedilnd'er affording a long baseline without requiring the soldierY or hunter to carry both the" gun andv an additional instrument; (3) providing a small, compact and lightweight range-nder attachabl'e to any military or hunting shoulder firearm without requiring major alterations of the firearm or interfering with its primary utility, and with its front elements attached to` the gun preferably independently of the mounting of its rear elements; and (4) providing such a range-finder and a settable rear sight combined for automatic coaction in the setting of the elevation by the action of iin-:ling the range.

Referring to the particular embodiment of the invention shown in the drawings, the general or range iinding diagram of Fig. 1 shows in plan view a suitablev method of holding the firearm for this operation, together with an optical diagram of the triangulation of the rid'er with the target T. The target distance or range i's represented by the length of the line TA. The baseline AB is the line between the rear' or beamcon'rbining elements or unit A and the remote or front elements or beam-collecting and bending unit B. The line TA is the direct line of sight. The line TBA is the indirect or deflected line of sight, bent at A to reach the observation point E.

The values of the base-line AB and the angle TBA are both known and xed. Thus AB is the lineal length longitudinally along the gun barrel between the front iinder elements, particularly the collecting and rst bending element,- reiector or prism, designated B, and the rear elements, particularly the combining and second bending element, reflector or mirror, designated A. Thus also, as to the angle TBA, this is the predetermined invariable angle subtended between the j longitudinal light path or axis from B to A- and that beam or light axis which when ben-t and reflected by the pre-xed reflector orprism B- wilt of the baseline of the finder, that is, the

travel along such axis or path BA as itmust do to reachthe' reflector A. The xed ang-le TBA could advantageously be but a prism B giving a slightly smaller known deviationangle, under 90, may be used. Thus the front reflector could wellbc such, and so lixed in position, that when the target T isat some mean range, as 400 yards, the direct image viewing line or axis AT will stand approximately at 90 to the base line AB, asV the Fig. 1 diagram indicates; in which case when the' range' is lengthened the rear reector must be rotated slightly clockwise to register the two images, while the gun is swung oppositel-y, displacing its muzzle and slightly from the target, these actions being reversed for' a shortened range.-

The angle TBA being xed, the angle TAB is cf course a variable one and is, for each operation, set or measured by rotating the rear deector A about its verticalaxis or pivot bearing,

as will be described. rllhe distance TA is the y range, and its value is determinable from the known angles and the length of the included baseline; and the value isusually indicated by a sca-le with an index or pointer and graduated to show the range, the adjuster or thumbscrew t3 being. the means of shifting angularly the renector.

Figs, 2 to 6 are diagrams of various elds of view obtainable in diiierent ways through the optical elements of this invention, with the (triangular) imagesV of the target separated or in register, as will be explained in detail hereinbelow.' Y

The perspective view of Figs. '7a and 7b shows the breech portion and muzzle end of the army riiie with its front and rear sights and adjacent parts of the range-finder mounted near the ends oi the" barrel Il-l.- The several views of Figs. 8 to 12 show more completely the rear sight and rear finder elements and their mounting and operating means, to be more-fully referred to.

The gure group 13l to 17 shows front-end sighting and find-ing means in greater detail than Figs. 1 and 7b. The figure groups 18 to 1.9, and 20@ to 22,- and 2-3, and 2d toA 30, and 3l to 35, and 36 to 39 show rear-end parts with further' details of the sighting and nding means.

Figs. 40--42 show a portion of the rear-end mechanism, with a telescopicv instrument attac-hed at the observation ocular of the range finder, which may be desirable with excessive ranges or small targets.-

For the purposes' of further description, the relevant additions to the gun may be divided, as they are in Figs;v '7a and 7b, into two groups of parts, namely, the rear parts including the rear sight and adjacent finding elements with their mounting and operating means, shownvin Fig. 7a; and the front parts includingthe front sight andadjacent iinding elements, shown in Fig. 7b. These two groups, more particularly the near and remote optical elements or reectors Av and B, are separated, in an optical sense, by the length 'i base of the triangle by which the range is to be measured.

Referring first to the rear group assembly this comprisesan attached saddle-shaped base or supporting block- 5I, Figs. 8, 18 etc., hereafter called the saddle, built up oftwoseating bars connected by end piecesy best seen in Fig. 18,. the whole mounted iixedl'y upon the permanent bridge 52, andsomewhat to the rear of the cartridge-clip slots 54, by attaching screws or other means, not

shown; the saddle supporting directly or indirectly a number of other parts, including a frontward extension or shelf `'.iIY for the rear optical elements.

'I'his saddle or attached base piece ii! supports directly a two-legged open frame or upright guide piece Figs. 8, 23 etc., having dovetail tracks or channels S adapted to guide a dovetail slide or elevating plate 5l, Figs. 24 t0 30, and having a top bar or stop 58 to limit the upward travel of the slide 51 by the contact with the top bar of a stop pin 59 projecting from the slide, The upstanding guideway 55 has below its legs two peg extensions 55X iitting into a pair of holes MX in the front bar of the saddle, permitting the guideway to be secured as a unitary' part of the saddle. i

Loosely attached to the elevator slide 51 by a lower pin or pivot 60, allowing some swinging motion or play to prevent binding during lifting, is a horizontalcross-part herein termed the sight bridge, 6 l, which carries the apertured rear slight 63 shown as a plate. The liftable bridge 6I is centrally open to surround the upright guide or frame 55. Said sight bridge at will, to maintain a given elevation, may be clamped adjustably to the guide 55, at any selected height, as by a clamping screw B2, whose operating head or thumbpiece is seen at its righthand end, Figs. 7a, 8, 24 etc.

The sight bridge 6I, which carries the rear sight G3, may be operatively raised or lowered by the crosswise shifting or sliding of-an important mechanical element, a common adjuster, controller or cam means 78, Figs. 7a, 36 to 39 etc., to be further described; and the sight bridge and sight may also be lifted independently by hand temporarily to a high inoperative position (the adjusting controller 18 acting by an open cam) and may be fixed there by the clamp screw 62, before the range iinding operations. Thereafter the sight bridge may be unclamped by screw 62 and lowered into operative contact with the upstanding cam part or elevating face 11 of the common adjuster 18, thus to lower again the rear sight 63; and then if desired, range iinding having been effected, the sight bridge may be clamped in its lowered or shooting position by the same screw 62. Gn the other hand the rear sight carrying bridge 6I, or rather its follower Contact 716, may be maintained as by spring pressure in constant contact upon the elevating cam part ll', shown as an open cam, since wear is negiible, and indeed a closed cam could be used, with a follower acting to raise and lower the bridge and sight, thus giving positive positioning of the sight with an elevation corresponding always with the range which the range-finder setting may represent.

lThe rear sight 53 may take different forms but is shown as a small plate $3 formed with a sighting notch or preferably a peep hole 55 as seen in Figs. 7a, 10, 12, 26 and 27. It is mounted for horizontal slidable adjustment upon the sight bridge 6i and rises and lowers with it, for elevation. The slidable sight has a threaded rear lug or nut 64 which extends through a horizontal slot into a transverse way SEX formed in the sight bridge rear wail, thereby to permit left and rightward adjusting shift of the sight.

By the structure thus described the sight bridge 6l is adapted for windage adjustment, carrying laterally slidably the rear sight or peep-hole plate 63, whose threaded lug or nut 64 is shiftable in f the bridge slot and slideway tl X. Engaging the threads of this lug or nut is a windage setter or screw 56 borne by the bridge and having a thumbpiece or knurled head 6'! at its left end, and there being a compression spring t8, Figs. 'if1L and 12, at the right, opposing the rightward movement of the nut 6d, and thus preventing loose play. This arrangement provides the conventional type of windage allowance by lateral adjustment of the rear sight.

To ensure sight through the peep-hole in all adjustments an elongated hole or through aperture 69 is provided in the rear side wall of the bridge 5 l and a similar but vertically wider aperture 'iii is formed in the slide 51, see Figs. 25, 28 and 30, thus to permit an unobstructed View through both bridge and slide. The front wall of the bridge is also cut away at 1i, Fig. 28, in the line of sight, for the same purpose. The nearby opening 'l2 in said front wall is provided for access, during assembly, to the stop-pin 59 of the upright slide plate 5l.

The illustrated sight bridge 6l carries at its rear side above the rear sight a graduated scale 13 attached adjustably in place by a clamping screw lli, which is to be tightened iixedly after the initial or test sighting in of the rie, Figs. 72, 8412, 24, 25; thus standardizing the position of the scale relatively to the sight. The peephole plate or sight t3 carries a pointer or index marl: '15, Figs. 7a, 12 and 26, which registers with, as it shifts along, the graduations on scale 13, thus to assist the operation and indicate the ad,- justment for transverse winds.

To take part in its vertical adjustment the sight bridge 6I has a downward contact projection or follower l5, Figs. 721, 25 and 28, .adapted to bear down and rest upon the top cam part or face il of the adjuster or cam means "it, so that the cam as it slides leftward or rightward can raise or lower the bridge and rear sight, according to the contour of the cam face. This follower 'i6 and parts between it and the sight may be considered as constituting a device for setting the sight, operated by the Cam part 'l1 of the adjuster 18.

This common controller or duplex adjusting cam lis mounted to slide leitward and rightward upon the upper face of the saddle block 5l, the cam body i8 preferably carrying not only the sight setting cam part but also the finder setting cam part. The duplex cam comprises the upwardly extending cani part l1 with contoured face for sight elevation and the rearwardly extending part 86 with contoured face for rangeiinder adjustment, see especially Figs. 7a and 536-39. For its adjusting movements the cani body has a downwardly protruding threaded extension or nut i9 formed with dovetail sides il@ prolonged beyond the nut and adapted to engage and slide between the matching or opposite sides 3| of the guiding slot or transverse recess formed between the front and rear Vbars of the saddle 5l, Figs. 8, 18. The threaded nut 'i9 of the adjuster cam is engaged by the threads of an adjuster screw 82 which at its right end carries a knurled thumbpiece or screwhead 83, Figs. 7a, 8-12, 36-37. r,the screw shank is formed with a circumferential groove 812 which is engaged by a fixed pin 85 upstanding from'the right end of the saddle, Figs. 8, 18 and 19, these parts preventing the longitudinal movement of the screw t2 and thus compelling the rotation of the screw by the adjusting knob 83 to'slide-the control cam 'i8 transversely upon the upper lface of kthe saddle, and, by the contact of top cam part i1 with the pro- 'further describedfthe'rear optical elements, es-

pesi-ally :therotar'y refiector,'inay :be 'said to `be provided iwith 'a 4settingcontriv'ance or meciianisin, in this 'case 'eomprisingamovable arm or swinging lever 88 and the terminal `Contact or o'f Athe duplex cam'nieans 18. The A'conimoryait vtis'ting means or dtipiex'controiler may'thus oe considered as comprising 'the cam means generally 'or its body "F8, 'thesldingpperation Voi 'which 'by thecon'troller screw 82,"33jserves'both to actuate the cam part S5, operating through members f8? andZtSa-nd othersfor finding theiange and to 'actuate Vthe cam part 11 operating `"through the elements "i6 Jand "Sl to set yo'orrespondingly the Vertical vposition'cif `the rearsight and 'thereby/the 'elevation of lthe gun, A'forany given'distance of "target 'The companion nam parts, "always vin definite relationship, 'provide automatic operation -and `'timing 'of range v'finding and Agun--elevationz whichever A'one -be'ing under observation `during 'settingthe 'other receiving the'fcomplementary "setting Y A Thus, the duplex adjusting o'rfdoi-ible wedge `dam T8 has Eits 'rearf'campart `'or eiiftension 36 "formed-with "a cam "face taking fp'aiit 'in rangetact with the free right end 99 of the=longfvarm f.'

fof a second Atransverselever '39| `ipivoted fon "the "against the open cam 8`6 by=1a spring-83. 'The 5secondKorfshoiitend f theseoond leva-.91 Shaving tuta-mi'uou'te swing, 'ez-igages'theroundedfendnia *threaded into/and carriedby the-reargoose-neek or extensionarm F9 5X Y.ofi/a-svingabile'foaifriage 85 vhaving an interior .round 'hole @by fwhioh 'it Lis of the beam-combining rorirear lopti'cal unit as 'range-finder setting. "lhe :"Seiiew'id imay iconvenliiently be fused 'initiallyfto standar'dizeithe iadjust- Tnientv of, for to v"siglit in,thelrangen`der.

The `carriage L95, ifotatalble fon-upright -pivot 97 fduiiinglimage registeiiingaoperations thebase line "lengthfbetween the remo'tefand fnear Arle'ieotors lis not hanged.

The thrust ofthe 'snor-tam -o'f liever 9i acting optical 'element 'A "theminute angular `adjusting motion `necessary Afor range "nding purposes. With t`he "cani face' S6 suitably 'designed and "iaid out, the scale H2 may be ruled with equal-sealer increments for equal increases of range, thereby afiordingconv'enienoe in range ndingandsimpli'fying the laying 'out of "the companion nam 31d whifih 'ei'evates Jtiiereen: sight; `Wh'ic'lfisight may have "a separate Vindicating scale, although fthe interconnection of the 'two cams Aand "the parts 'beyond jniakes "this unnecessary By the d'escribed 'elements'l `to' 94 is :provided a mechanie oal train, or operating "conti'ivan'ce, 'extending from the duplex adjusting ncam T8, *85, "by `which the-cairiagef andthe rear opticalmenibe'r or refiector A 'thereon 4are g'iventhe'n minute'angulai setting. adjustments underthe'iangeending principies already explained; 'while 'the vtrain'i, 'E1 :and SEd constitutes 'the 'device or "connections 'rom-eam"i3,'r`iVtotherearsight 63.

'The swinging 'optical carriageil by `reason 'o'f yits verticalpivdt 'helenan rotate ai'oundtheixe pivot 9'1 (Fig. 18) onthe'sadie extensionifi, w'ticih 'pivot isslotted at" Q8 4to `receive and hold a iiat or stripispring *SS'wliioh tmay be X`initially curved or straight andwhic'h contacts the 'carriage '$85 at 19B, "Fig," 20, andwl'iioh, being'undei 'constant'bending strain for counterolookwisecarriage swing, :tends to vpress the carriage '-contact screw 913 against theshoit arm of leveryi, thus keeping the 'leveriiee Loi ,loose piay,-'andensuring continuity of train. lThe"piVoted oaiiiage'g z'is held downin dlose'c'ontact upontheupperffac'eoi Athesac'iolle'i by any conVenieritoverhangingpart such astne headof a post fir-screw "mi V'(Figf) passing `through aslo't iEEiin ithe 4carriage,'and Screw-threaded in'to 'the 'saddle eXtensioii'fS-Y;

the 'post y'head `iria-ving -a woking I"t to 'permit 40 1carriage swing.

pasaiiei tof -fescribedintation *of "the Whousing@about -its ,own horizontal f axisV -iu'neti'ons for adjustment 'to v.hr-ing ".tietaifget :into view Ybeforewitsrrange finding `rota'tion aiout veiitical aXis-'toficaiiifiage swing. he voptica-1 'base 9.5 iis 4'assumed'lto haveftaeen fixed to the pivotedfoaiiriagea ioy a pin Sor other Pmeansfnot shox/vn, `aiter 'the .base `has fonce been 'set vaccurately to place 'the.;1^ear:optical elem `inen't SA 'attheipre'deterrnined base line distance 'ifroni thezi-riont beam-'collecting 4"unit B.

'l1-he' housing M6 ."isstiown iwitlreeveral optical 13 openings or windows. See Figs. 7 to 11 and 31 to 85. Openings its and 09 are righthand and lefthand opposite side windows forming the op posite ends of a lower light beam passage or shaft for the substantially direct viewing of the target, the direct beam TA Fig. 1 entering the opening 'E08 and leaving through the opening HBS. Another opening HUX, Fig. 10, is an end Window for the receiving face H of the optical reflector A which is shown as an isosceles right angle deecting prism receiving longitudinal beams reilected from the front beam collecting unit B. The fourth housing opening HIX is a left window for the exit face Hi of the same prism A, through which face and window the beam BA after bending passes transversely out of the housing to the observers eye. The lower and upper exit openings I6!! and HEX preferably are physically a single window opening, the optical dividing line i3d between them, Figs. 11 and 35, being at the bottom surface of the prism, this being referred to as the halving line, stand ing between the two observed images. See also Figs. 2-5. These openings in combination with the reflecting prism A may constitute the ocular of the range-iinder, presenting to the observer,

adjacently one above the other or side by side,

'the two images, direct and twice-reflected, to be yadjusted into coincidence or register by the range- `iinding operation.

The ocular, by its housing Hill-406, thus provides apertures for the separate admission of the two beams BA and TA (or TE) and `for the .joint or adjoining egress thereof for comparative observation, e. g. with one image at each side `of the halving orcoinc'idence line i311; `their registering consisting in adjusting the iirst image along said line until it aligns with the second image upon the reference line l25.

For convenience the saddle l is shown as carrying a range scale H2 marked oil in any appropriate unit of target distance between the upper and lower limits within which it is desired to use the range-finder and/or the rear sight. See Figs. 7, 8, 10, 18 yand 36. The drawing shows rangesfrom 100 to 600 yards as appropriate for the army rie as used without a telescope. vA pointer or index H3 on the slidable controller or double wedge cam 'I8 registers with the graduations of scale i l2, and thus'indicates at all times the range for which the rear shooting `sight is adjusted. By screws H4 (Fig. 18) the scale is mounted on the saddle, with transverse slots to permit initial adjustment of the scale for standardizing its position when' the range-finder is being adjusted or sighted in.

The rear optical element A is essentially a reiiector to cha-nge the beam TBA from longitudinal to transverse direction relatively to the base BA and the gun barrel, thus bending andfdirecting the image to the eye in position juxtaposed to the direct Yimage seen along the line TA for observation and comparison during adjustment. While a mirror could be used to bend the beam or ray, a prism is shown; and in Fig. `43 is presented an available form of prism A, being a conventional right angle triangular prism,.pref erably isosceles.

The front sight H5, with its hood H5, and the adjacent optical elements, are shown in Figs. 7b and 13 to 17. The front sight may be mounted in any usual way at the muzzle end of the barrel H1, in front -of and higher than the optical elements. The latter comprise a beam-collecting unit containing the reilector B enclosed in a housing H8 whose bottom wall or base 'H9 has depending dovetail projections shaped and taperedto Vengage with wedging fit the upstanding ears of a strap l2@ encircling and clamped to the barrel. The housing H8 may be locked in place by a pin l2! and the strap may be xed against rotation by a lug I 22.

The housing H 3 for the iront optical means is formed with two optical openings or windows 5235 and IMX respectively facing rightward from and rearward along the base line and barrel. Within is the reflector B, shown as an isosceles right angle prism as in Fig. 43. The rst prism face |23 receives the lightbea1n TB from the target through the window MSX while the second face |24 vtransmits through the window IMX the rearwardly deflected beam to the reflector A, which may be a prism as Fig. 43, oi the beam-combining rear optical unit in housing it, which unit receives the beam through its front or i'lrst prism face Ht, and transmits it 'by its second face Hl. The prism B in the housing i I8 has an etched line or cross hair E25 either centrally on its diagonal interior reiiectn ing surface, or'on its rst or entering face as in Fig. 7b, this hair line serving to ensure uniformity in the use of the optical system. The image of this reference line is the hair line 25 seen also in the diagrams Figs. 2 to 5.

The reference `line |25 is preferably so applied as to be observed substantially at right angles to the halving line 134, and to appear, as seen in Figs. 2 etc., as substantially central of the eld of observation; and the line las also is preferably about central, thus halving the eld, due to the design of the housing its and the disposition of its windows, especially IGS and HEX,

`as'seen in left elevation in Fig. 1l. The reference or hair line Yi 25 serves as an index or guide means, standing at right angles to the halving line. This element is important when one `of the observed beams is received direct from the object; it may be placed in either beam and is carried by the gun, being Vpreferably in the reflected beam and near the iront or remote reflector, and therefore as far as practical from the eye.

The housing H3 may be positioned upon the barrel at a predetermined point lengthwise, according to the desired base line length, being shown closely to the rear or the front sight il'. `Of course its rst window must look unobstructedly upon the target and the housing must not obstruct the iront sight as viewed from the rear sight. rChe housing and the ilxed front sight may be combined in a single unit if desired, attachable as a whole. For excessive ranges of shooting the described range-iinding means may be supplemented by a telescopic means. Figures 7e, 40, Lil and e2 illustrate a short type of telescope l2? available for the purpose, this being shown attached to the saddle 5l by anfadded bracket l2fs, and being arranged with its ocular E28 optically in line between the ocular of the rear or beamwombining unit and the eye. The telescope may be equipped with a cross hair located in its common focal plane rather than using a hair-line in the beamcollecting unit.

The principles of this invention lare not limited to the particular optical and mechanical equipment 'shown by the drawings, since various kinds `of mechanical and optical members, of different -character and degree of precision or usefulness may be substituted or added according rto the needs of the user. `Such means as hoods, iris :stops or eld stops, or light-shielding tubes Y .15 surrounding the flight .path :along 'or Fbeyond the base eline may'ibe added without departure from the principles of `.theiinvention As one example, an amici prism is sometimes to be preferred to the `right angle prism of Fig. 43 for either .the beam-collecting un'it B Sor-the beam-combining unit A, lor any suitable roof-prism type'oi reflector may beused. As another variation, the prism A in'housing .we may occupy 'the bo-ttom half or sement-her area instead of the upper half ofthe housing. Or, what has been termed the direct View TA or the target 'might reach the eye via `some reection or bending so long as the base line principle Yis not impaired, the two 4utilized 'light beams being divergent from the target by a vmeasurable and effective, though small, angle. Or, ya prism with only partly fsilverecl reflecting face.

Reviewing the embodiment of the invention illustrated by the drawings, the first or iront one ofthe light beams, namely TB, is received by the front isoseeles lright-angle deilecting prism E through its iirst'win-dow and prism face |23 and 'is deiiected interiorly `by the diagonal face to make its exit through the second face |213 of the saine prism and through the housing rear window, passing thence `to the preferably similar reflecting prism A in the'rear housing litt, entering through the rst window and prism face H whence it is deflected lcftwardly to make its exit `through the second prism face il and left window, and passing ythence to the eye. The other light beam TA is received direct, or eiec tively so, from the target as through the right side window W8 in'housing IM and passes thence preferably without change out through the left window W9 yto the observation point or eye E along with the deflected beam; thus affording a :pair of comparable images which may be viewed one above the other to secure registry as in Fig. 2 or side by side to secure registry as in Fig. 3, or .with full superposition as in Fig. 6, or by inversion vis-a-vis Vor symmetrically as in Fig. 5, according to the optical elements used and their ar-rangement, as will be further described.

The optical-system as thus illustrated will produce an veffect as in Figs. 2 to 4 with -two erect imagesof the target, or with one image inverted as in Eig. 5. By an integration of Athe manual movements of thetra-nsversely held gun (Fig. l) in relation to the target T, and the settings of the light-deflecting prism .A in the rear housing |65 in vrelation to the rifle, the images viewed by the observer may be brought into registering alignment or otherwise .into coincidence. The relative movements .may .appear somewhat complicated,

as described, but inasmuch as the eye continuously observes the effect of every movement, the .rangeinding vactions are made almost instinc- .tively,.so .thatpractically ythe operation is essentially simple. For the sake of simplicity in the `further description, it rwill be assumed that once the image pair is brought into the eld of ob- `servationthe .rie ywill be held stationary, and also that .all movements of the vindirect or de flected image are effected by the angular setting movements ofthe prism Acontained in the hous- .ing |95 .carried ,on the rotatable Ycarriage E5, whose swing is .effected by the manipulation of -the .thumb piece or knob S3 or .the adjuster or duplexcam 18.

One mode of operation may be as follows. Assuming first that Lthe firearm vor rie has been .positioned so that .a selected point of the direct target image `1.29, Fig. V2,app.ears .at one side, .in this case 1the underside, ofthe 1ineof-separation or halving line .1.34 where :it .intersects with-the reference vline .or cross hair |25, -thena proper manipulation .by `the `projecting pin Vor handle lill, Figs. 2a and 31-35, .willrotate slightly ,the housing m5 and its contained prism -A-.about the housing llongitudinal -aXis -to 1bring .the deflected image |36 into the ield .of -view and at a slight distance above the halving line and above the direct image 129 y-as ,seen in Fig. .2a.

-By va further rotary adjustment of the housing l by :its handleidi kthe .deflected image |39 may be shifted downward so ,that the selected `point or apex, being any convenient lobject in `the -target, -is brought Ivery-close to, Ybut still beyond -or slightly above, the halving line |34 which :is

usually the trace or lower-edge of the bottom of the prism A; -as seen in Fig. '2b. This supplemental vertical shift of the deflected image toward the halving-line -is advantageous but'islnot ssential so'long as the-=two images are in com- .parable positions in --the field of View, inasmuch as alignment of `the two :images alo-ng vany part yof the reference vline |25 is all that is required for .the range-iinding'operation, when such a 'lineis provided.

To attain register, the'deflec'ted image i may now be shifted zhorizontally or `in a direction parallel to the halving line untilitsselected-point, shown as an apex,'is on the referenceline |25, as appears lin Fig. 2C. This adjustment is ymade -easily as 'by the thumb and Aindex finger turning vthe knurled lhead or knob -83 `which operates 'through the controller or wedge cam i8 to actuate the lever 88 through the contact of its point 8l vwith cam part 8G, and vthereby ythe Alever eil lthrough its contactwithlever at 'te and thereby the pivoted carriage '9.5 through Yits Contact `with the levert! at the screw 94, and thereby to adjust and set the prism A in the housing I carried. by the carriage. At the same time the sight bridge .'Gi 'is shifted vautomatically andcorrespondingly adjusted and set through the contact ofthe projectionl' with cam part ll; the vertical movement of 'the sight bridge carrying with it the plate or sight t3 and its peep-'hole 165, to the correct shooting elevation for the found range. The sliding movement of the common-adjuster or duplex Wedge-cam 'i3 also carries its pointer I3 over the scale H2 to aiorcl a reading of the range.

In the diagrams, Figs. '2 to '5, the substantially direct or rear image |29 of the target appears 'in the (lower) eld |3| of direct view, meaning the View of the target seen along the beam TA; While `the other image |39, seen along the beam TBA,

Fig. 4 shows the corresponding condition .for

someposition of thesflrearm other thanhorizontal or vertical. Inboth of these cases vthe apexes have been put .in register, 4that `is,.both falling upon the reference `line 125.

Fig. shows the eld of view when the deflected upper image is inverted, as by a special or roofedge prism or equivalent substituted for either erect prism shown, and brought into alignment or coincidence by a shift like that in Fig. 2G.

Fig. 6a shows how the complete coincidence of images in the field of view may be obtained; as by the use of a semi-transparent reflector which occupies the entire passage area of housing Hifi; the full area of the through window Hi8-i539 being open for the direct View `of the target through the transparent mirror or prism, whose reflecting surface may be thinly silvered. Then, as shown in Fig, 6a, there exists the field ESI of direct view, with the deflected image eld E32 superimposed thereon, while the deected target image 36 is seen approaching full coincidence with the direct image 129. Fig. 6b shows the full coincidence attained, of the two images at 133, which is the general equivalent in results to Figs. 2, 3, 4 and 5, but with the advantage of more eX- act visual observation of true register for range finding with the base type of finding means.

The curve of the range-finding contact face 216 of cam i8 is derived from the curve obtained whenI range distances are plotted as ordinates and the required angles of rotation of housing |05 and its prism Aare plotted as abscissas. Likewise the curve of contact face T! is derived from the curve obtained when distances are plotted against successive increments of elevation of the rear sight as required for successive ranges and selected trajectories. It will be evident, therefore, that these two curved cam faces, cooperating in unison, first, translate the curve representing increments or angles of rotation of the deflect prism A in housing |06 into a straight Aline and thereby produce the uniformly spaced scale H2, and second, simultaneously translate this straight line into the curve of the corresponding increments of elevation of the rear shooting peepsight aperture 65.

These cam contours of the adjuster cam are preferably designed, as shown, of extended length so that they may avoid undue steepness of slant and be more easily manufactured to the degree of accuracy required of them, while minimizing wear. The curve of cam face 'l1 is such as to be responsive to the trajectory pertaining to the particular ammunition with which the gun is to be red.

The minuteness of the quantitative values in'- volved in range-finding triangulation emphasizes the value of the substantially long base-line AB which is available with the manner of use of this invention upon a shoulder firearm. Even-with this ample base-line, of say inches, the rotation of the reflecting prism A required for a shift from 100 to 200 yards is small, and may approximate l2 minutes of angle, and for a shift from 500 to 600 yards is much smaller, about 0.75 minute or 45 seconds of angle, which is substantially below the average resolving power, about 1 minute of angle, of the human eye; thereby usually presenting dimculty in distinguishing between and adjusting for target ranges of about 560 to 600 yards.

However the aligning power of the eye is far better than its resolving power, being of the order of 4 to l2 seconds of angle of the distant targets, which fact, with this invention, substantially overcomes the visual deficiency, in range-finding, by the bringing into register of the two images, reflected and direct, by the adjustment described. Since, between 500 and 600 yards the angular dif- A blocking ment.

ferentiation is about 45 seconds, the eye power of alignment ofv l to 12 seconds is far more than ample, and would serve for ranges considerably beyond 600 yards.

While the quantities recited are well above the stated limits of the power of alignment possessed by the unaided normal eye the addition of a short telescope of prism type will greatly improve longrange accuracy; suoli an optical telescope being shown in Figs. 40, 4l and 42, and indicated in dash lines in Fig. 7a.

It should be noted that if the actual target contains no salient or sharply dened pattern or area, as a vertical line or apex, which can present a pair of images adapted to be aligned across a horizontal line of separation, as the halving line i3d of Figs. 2 to 6, 11 and 35, the firearm may then beswung about into a vertical or inclined position, as represented respectively by Figs. 3 and 4. When the actual target is devoid of any well defined point or line, some prominent feature of an adjacent object may serve as a substitute in obtaining the range of the actual target.

The following details are noteworthy: The base range-finder on the firearm as described may be used by the shooter in the standing, sitting or prone postures with almost equal facility. The range-finder on the firearm may also be used conveniently as a periscope for reconnaisance, as by pointing the gun upwardly and preferably the direct view window m8. The knurled heads oradjusting knobs, il?, for rangeiinding and t7 for wind allowance, may be equipped with click mechanisms to indicate audibly the changes made in gun elevation or windage adjustment, thereby to permit easy correction of aim from the observation of the point of impact of a. previous shot. l The knurled head or thumbnut S3 may also be graduated around its rim or elsewhere thereby to serve as a subdivider of the spaces on the scale H2 and afford ner adjust- The range-finder means and the cooperating rear sight means are both of such compact shape and size as to be practically mountable on the gun and to offer no obstacle to the usual operations of the ring bolt, to the loading by clip or singly, to the ejection of the empty cartridge, or to other conventional operations; while the embodying of the invention on the gun sacrifices none of its regulation functions or facilities.

On the other hand, the range finding elements and features hereof possess certain novel utility apart from their use on a gun, namely, by mounting them on a supporting bar representing a barrel, making use of the disclosed elements numbered 'i8 to H4 and H8 to |36, or simplications thereof, without using the other illustrated parts pertaining to the gun or its sighting means. in this aspect the range finder is of the fixed base type, with a rigid bar or support lll of at least full length of the optical base line and on which the other elements are carried. These include the near reflector A, located at the near end ci' the base, whereat the observations are taken; and the remote reector B at the far end thereof, the latter being iixedly mounted at a slant to act upon the iirst light beam TB received transversely from the distant object 'I' by bending the beam through approximately a right angle and directing it longitudinally along the base line to the near reflector A. The near reflector has a suporting turret or carriage upon which it is mounted for angular or rotational adjustment with the turret about an upright axis, whereby the reflector A may be set to a variable slant to gassen Y I9 act Laon the received once-benty rst beam and bend aa in through. approximately a right angie a direction away from the object and teward the observers eye E for viewing this indirect first image adjacentiy to a second or direct image thereof, suchA as the direct view of the target which is seen. alongside of the twice reflected image. To determine the range, the described manual setting means may be used for causing rotation of the turret and thereby a fine angular adjustment of. the near reflector whereby, under observation, such two images may be brought into mutual register or coincidence with differing distances of object, and along with these the scale and index, as before, to read the setting thus attained and thereby to determine the range of the object. The manual actuator or thumbpiece t3 operates the turret-rotating mechanism which includes the cam 11, 85 and a motion reducing train 8'1. to Sdi actuated by thc cam and connected to an extended part or arm of the turret to give the latter and the reflector the desired fine angular adjustment necessary for scientific determination. of the distance of the object. It is further useful for range finding per se that the reflector is contained in the housing its which is mounted on. the` turret and has window openings for the admission and egress of the two light beams, with the additional facility of a swivel mounting ofthe housing on the turret to permit manual rotational adjustment of the housing and reiiector about a longitudinal axis parallel to the baseline, thereby preliminarily bringing the first image to a. convenient position in the eld of view before effectingv the rangeiinding adjustment. These two rotational adjustments of the near reflector A operate as follows, the turning of the housing on the carriage acting to shift the. rst image toward' and from the line I3il of separation, Fig. 2,. while the angular rotation of the turret, housing and rei-lector about their upright axis operates to shift the first image along the line of separation so that said image 53) and the second or direct image |29 may be brought into register at the reference hair line H25, in which condition, Fig. 2C, there is register, and the range of. the object becomes indicated on the scale and. index.

Referring further to the reference or hair line 425, this serves as a. guide or index for locating one of the two images withreference to the other, assisting in adjustingv a selected or axial ray of either one or" the light beams. to a predetermined. location, or the selected rays of both of the light beams. The index guide [25 is preferably on or near the remote-reflector of a rst-lightbeam and alici-ds uniformity, and the necessary accuracy, in bringing the two images into coincidence, when the second beam is a direct-viewed one. While shown as astraight or hair line it could be of various kinds, asan. odd number of parallel lines, a number of small. circles, concentric or aligned, or other forms, whether at a surface of reiiector, or interior or exterior thereto.

The range-finding. means may be considered as having two optical systems for comparison, delivering their light beams and images adjacently at the observation point; at least one, the first, of said systems being indirect, having a remote nrst reflector and. a near second reflector, along the base line, and set at angles for double reiiection of beam as described; andthe second optical means being either indirector direct, but preferably direct, and so shown, for gunsi'ght purposes; this arrangement calling for the use of the refer- 20 ence guide or index means 1'25 to aid in setting the parts to achieve coincidence of images.

There have thus been described a shoulder nrearrn or gun with conventional. sighting means, together with a range iinding means, operable in a manner to embody the principles of the present invention; and since many matters of combination, construction, arrangement and detail may be variously modified without departing from such principles it is not intended to limit the invention to the disclosed features specifically disclosed except to the 4extent set forth in the appended claims.

What is claimed is:

l. A manually borne gun carrying rear and front shooting sights with` a shiftable rear .sight setting device operable to coordinate the gun elevation with the range of the target; and said gun carrying also a base-type coincidence rangelinder means having first and second.y optical systems delivering images ci the distant target at the observation point, and the first system having rear and front optical reflector elements located near the andV iront sights respectively thereby afiording a base line between saidrefl'ectors arranged adjacently lengthwise of the gun-barrel, said range-under having a: shiftabie setting contrivance operable under visual observation to set the nder to correspond with the target range; the front reflector being mounted at a slant to the base line to bend the first image beam to the rear reector, at the position of which the observations are taken; and common adjuster or controlling cam means operable te shift both sai-:l setting device andv said setting contrivance in such coordir on that the gun elevation in any setting of the sigh-ts correspondswith the range deterniinedl by the setting of the' range-finder; together with aturret or carriage turnable on an upright thev rear reiiector being mounted to turn with said turret thereby to impart angular adjustment to the rear reflector, with means for setting the' turret tol vary the reflector position and thereby the angle of second reflection of. the first beam in a direction :Eromthe distant object, for observing ad-iacently the two*` images in bringing thern into register; and there being an apertured carrier or walled housing which carries the rear reiiector and is mounted upon the turnable turret to swing or tilt thereon about an axis substantially paralisi to the base line and independently of the turning of the turret and. rear reflector about such upright axis', whereby the carrier and' reflector may be swung to bringv the irst image into` a field of view adjacent to that of the second image' in advanceY of turning the turret to shift the first ii age into coincidence with` the second image.

2. A manually borne gun carrying rear and front shooting sights with a shiftable rear sight setting device operable to coordinate the gun elevation with the range of the target;V and said gun carrying also a base-type coincidence rangender means having iirst and second optical systems delivering images ofthe distant target at the observation point, and the first system'. having rear and front opticaly reflector elementsI located near the rear end and front sigh-ts respectively thereby affording a base line between said reectors arranged adjacentiy lengthwise of the gunbarrel, said range-finder having a shiftable' set-V ting; contrivance operable` under visual observation to set the ii'nder to correspondv with` the target range; the front' reflector being mounted at a slant to the base line to bend the first image beam to the rear reflector, at the position of which the observations are taken; and a common adjuster or controlling cam means operable to shift both said setting device and said setting contrivance in such coordination that the gun elevation in any setting or" the sights corresponds with the range determined by the setting of the range-finder; together with a settable carriage or rotatable turret swingable about an upright axis adapted to vary the angular position of the rear reflector and thereby the angle of one of the beams for bringing the beams into mutual register; and a separate settable means or reflector carrier shiftable independently of the iirst settable means and adapted to vary the position of the rear reflector to bring one of the beams into position within the eld of View; the second optical system comprising a wall or structure providing apertures or passages giving an unobstructed direct view of the target in a viewing eld adjacent to the field of the indirect view provided by the irst optical system.

3. A manually borne gun carrying rear and front shooting sights with a shiftable rear sight setting device operable to coordinate the gun elevation with the range of the target; and said gun carrying also a base-type coincidence rangender means having iirst and second optical systems delivering separate images of the distant target at the observation point, and the iirst system having rear and front reflectors located near the rear and front sights respectively thereby affording a base line between said reflectors arranged adjacently lengthwise of the gun-barrel, said range-lnder having a shiftable setting contrivance operable under observation to set the nder to correspond with the target range; the front reflector being mounted at a slant to the base line to bend the first-image beam to the rear reflector, for re-reection to the observation point; and a common adjuster means operable to shift both said setting device and said setting contrivance in such coordination that the gun elevation in any setting of the sights corresponds with the range determined by the setting of the rangender; together with a carriage or turret turnable on an upright axis and upon which turret the rear reilector is mounted, thereby to impart angular adjustment to the rear reflector by the operation of said setting contrivance and thereby to vary the angle of second reflection of the first beam in a direction from the distant object, for observing adjacently the two images in bringing them into register; said common adjuster comprising a manual actuator or thumb piece and a contoured cam actuated thereby, and said setting contrivance comprising a motion-reducing train actuated by the cam and connected to an olf-center part or extended arm of the turret; and there being a carrier or walled housing mounted upon the turret and carrying the rear reflector and having openings or windows for the admission and egress of the two light beams; and the carrier housing having a swivel mounting on the turret to permit, independently of the turret setting operation, the manual swing or shift of the carrier and reflector about a longitudinal axis substantially parallel to the base linel thereby permitting preliminarily the bringing of the first or indirect image properly into the held of view before eecting the range-finding and sight-setting adjustments by the operation of the common adjuster.

4. A gun and range-iinder combination as in claim 3 and wherein theicontoured cam is mounted slidably for its manual operation, and is of contour to translate its uniform scale of ranges into angular reflector adjustments corresponding to such ranges; and wherein said cam is adapted to adjust the turnable turret and reflector to shift the rst image along the hah/ing line toward and from the line of coincidence, while the independent swinging movement of the carrier housing on the turret acts to shift such image toward and from the halving line; and wherein is a visible cross-line or hair extending at right angles to the halving line so that the first and second images may be mutually aligned while one is yet somewhat removed from the halving line, such cross-hair being on or near the remote reilector.

5. A manually borne gun having front and rear shooting sights near the muzzle and breech ends respectively of the barrel and having a shiftable rear-sight setting device operable to set the gun elevation to the range of the target; and operatively oombined therewith and mounted near the ends of such barrel a base-type coincidence range-lnder means having the barrel for its base; said range-finder for a first light beam from the target having a front optical reflector mounted slantingly near the front sight, and a rear re-reflector mounted slantingly near the rear sight, the same being operative to direct such rst beam to a common viewing point or eyepiece near the breech, the parts being constructed to provide for a second light beam a direct path from the target to such common eyepiece; said rangeinder having a shiftable setting contrivance operable under visual observation to vary the slant of said re-reflector to bring the reflected iirst light beam into coincidence with the direct light beam at the viewing point; and a common adjuster operable manually to shift said setting device and said setting contrivance in such mutual coordination that the gun elevation in any setting of the sights corresponds with the range determined by the setting oi' the range-finder; the front reector being mounted at a xed slant to the base line to bend and direct the first beam to the rear reflector, at which observations are taken, and the rear reflector having a rotatable carriage or turret turning on an upright axis by which turret angular adjustment is imparted to said rear reflector to cause such nrst beam to be bent through a variable angle approximating a right angle in a direction away from the distant object for observing in adjacent lields of view the two images, and said setting contrvance being operative for adjusting the turret and carried reflector, whereby under observation the two images may be brought into mutual register; and there being associated with said turret an apertured housing or carrier carrying the rear reflector and mounted upon the turret to swing or tilt about an axis substantially parallel to the base line, and manual means preliminarily to swing the housing and rei-lector to bring the irst image into a field of view adjacent to that of the second image; the housing swing operating to shift the first image toward and from the halving line between the fields, while the turret rotation operates to shift the rst image along the halving line toward and from the reference hairline.

6. A manually borne gun having front and rear sights near the muzzle and breech ends respectively of the barrel, with a shiftable sight-setting device operable to adjust the rear sight and gun elevation to the range of the target; and coopera- 23 tivev therewith and mounted near the ends of the barrel a monocular base-type range-finder operable upon the first of two light beams from the target and having a front reflector mounted slantingly near the front sight, and a rear rereector mounted slantingly near the rear sight, these being operative to transmit indirectly the first beam to a common viewing eyepiece near the breech; such range-finder being constructed to admit a second light beam on a `direct path from the target to the eyepiece; and such range-finder having a shiftable setting contrivance operable under Visual observation to vary the slant of said rear reiiector to bring the twice reflected first light beam into coincidence with the direct second light beam at the Viewing point; and a common operable adjuster manually to shift said setting device and said' setting contrivance in such mutual coordination that the gun elevation in any settingof the sights corresponds with the range determined by the setting of the range-nder; the rear reector being carried on a rotatable carriage or turret member turning on an upright axis and by the turning of which an angular adjustment is imparted to the rear reflector to cause such rst beam to be bent through a variable angle into position for observing the two images in adjacent fields of View, whereby under observation the two images may be brought into mutual register; there being a reference means interposed in the rst' beam path well frontward of the rear reiiector and providing a mark or upright hairline adapted to aidsetting for coincidence; and there being an apertured housing or carrier member for the rear reiiector, the same being mounted upon the rotatable turret to swing thereon about an axis substantially parallel to the base line, said carrier having manual means to swing it and the reflector to bring the first image into a field of view adjacent to that of the second image; the housing swing operating to shift the rst image toward and from the halving line between the elds, while the turret rotation operates to shift the first image along the halving line toward and from the reference hairline.

References Cited in the i'lle of this patent UNITED STATES PATENTS Number Name Date 789,783 Anderson May 16', 1905 1,968,002 Nowicki et al July 24, 1934- 2,058,484 Mihalyi Oct. 27, 1936 2,155,389 Arden Apr. 25, 1939 2,242,452 Cazin May 20, 1941 2,377,987 Whitmore June 12, 1945 2,378,282 Brueske June 12, 1945 2,426,812 Bennett Sept. 2, 1947 FOREIGN PATENTS Number Country Date 14,840 Great Britain of 1902 28,677 Switzerland May 11, 1903 387,702 Great Britain Feb. 10, 1933 551,510 Great Britain Feb. 25, 1943 

